BACKGROUND. The proposed research employs a computer-controlled analog of mass media settings. Development has already been completed of two large sets of persuasive materials (on policy issues and consumer products) for use in this or other laboratory settings. Research conducted in the past year has shown that the two sets of materials differ sharply in persistence of persuasive impact and in the relation between persuasion and communication memory (less persistence and stronger relationships for the consumer products materials). The combination of setting and materials has also been used successfully in initial tests of an associative learning theoretical interpretation of persuasion. PROPOSED RESEARCH. Research proposed for a two-and-one-half year period has as its aims: (a) analysis of, and development of laboratory procedures for studying, (b) the information processing strategies used by mass communication of audiences, (c) analysis of the effects of the independent variable of message exposure duration, (d) testing of theory-derived predictions about conditions that should produce delayed persuasion (i.e., sleeper effects), (e) development of new unobtrusive measures of message retention for use in hypothesis testing, and (f) applying the computer-controlled method to a recently developing area of persuasion theory--cognitive response analysis of persuasion.